The present invention relates to a mowing head used for a mower, which rotates a cutter to cut weed.
Generally, a cutter cord type mowing head includes a case, which is detachably connected to a rotary shaft of a motor installed at a distal end of a manipulating rod, and a reel, which is accommodated in the case with a cutter cord wound thereabout. A manipulating member is movably received in a center hole of the reel. A coil-like spring constantly urges the manipulating member to project downward from the case. Further, a phase angle changing mechanism is provided to change the pivotal phase angle of the reel with respect to the case in cooperation with the centrifugal force of the cutter cord when the manipulating member is hit against the ground.
When the mower using the conventional cutter cord is used for a long time, the distal end of the cutter cord wears out. Thus, during weed cutting, the manipulating member is hit against the ground or the manipulating member is manually manipulated after stopping the rotation of the cutter. As a result, the phase angle changing mechanism, which is located between the case and the reel, relatively rotates the reel with respect to the reel by a predetermined angle. This rewinds the cutter cord and adjusts the length of the cutter cord.
Conventionally, the following has been proposed as the structure of the manipulating member.
(1) Mold the entire manipulating member from synthetic resin.
(2) Form an opening is formed in the bottom potion of the manipulating member, which is formed of synthetic resin, fit a metal protecting member in the opening, insert a bolt, which is connected to the protecting member, in the opening, and fasten the protecting member to the manipulating member with a nut (refer to U.S. Pat. No. 4,524,515).
However, the prior art example (1) has a shortcoming in that due to contact between the manipulating member and the ground and repeated hitting of the bottom portion of the manipulating member against the ground during weed cutting, the bottom portion of the manipulating member wears out and becomes damaged at a relatively early stage.
If the bottom portion of the manipulating member wears out at an early stage, the entire component must be replaced even though its other functions are normal. This is not economic. Further, this increases wear and dispersion of the resin forming the bottom portion of the manipulating member and pollutes the environment.
Additionally, the spring that urges the manipulating member downward contacts the top surface on the bottom portion of the manipulating member. This has a shortcoming in that the movement between the top surface on the bottom portion of the manipulating member and the spring causes wear.
Prior art example (2) solves the above problem regarding wear of the manipulating member. However, the repeated hitting of the manipulating member loosens the spring. In this case, the protecting member may fall off or fall apart. Further, a spring receiving seat, which is located on the bottom portion of the manipulating member, wears out. Thus, there is a shortcoming in that it is burdensome and difficult to install the protecting member.
It is an object of the present invention to provide a mowing head used in a mower that suppresses wear of a manipulating member, reduces the number of the parts to facilitate manufacturing and assembly, and prevents a protecting member from falling off or falling apart.
In addition to the above object, a further object of the present invention is to provide a mowing head used in a mower that suppresses wear of a spring receiving seat.
To achieve the above objects, a perspective of the present invention provides a mowing head used in a mower. The mowing head includes a case detachably attached to a rotary shaft, which is located at a distal end of a manipulating rod of the mower, and a weed cutting tool, which is attached to the case. A bottom portion of the case is formed of resin. A protecting member is arranged in the bottom portion and insert molded using a material having an anti-wear resistance characteristic that is superior to that of the resin.